Antibody·An antibody (Ab),·alsoknownasan immunoglobulin (lg),·is a large, Y-shaped protein·produced mainly by plasma cells·that is used by the immune system toidentify andneutralizepathogenssuchas bacteria and viruseshttps://en.wikipedia.org/wiki/AntibodyStructureofanlgG2antibodyCreatedfromPDB1IGT,PMID9048542
Antibody • An antibody (Ab), • also known as an immunoglobulin (Ig), • is a large, Y-shaped protein • produced mainly by plasma cells • that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. https://en.wikipedia.org/wiki/Antibody ; Structure of an IgG2 antibody. Created from PDB 1IGT, PMID 9048542
AntibodyThe smaller(light) chain-25,000and iscommontoallclassesThelarger(heavy)chain50.000-77,000andisstructurally distinct for eachclass orsubclass.Thepolypeptidechainsarelinked togetherby covalentandnon-covalentforces.CLTLS,TsinghuaUniversit
Antibody • The smaller(light) chain -25,000 and is common to all classes • The larger(heavy) chain - 50,000-77,000 and is structurally distinct for each class or subclass. • The polypeptide chains are linked together by covalent and non-covalent forces. CLTLS, Tsinghua University
Antigen-Antigen-bindingbindingsitesitePapainHN*NH,cleavageNHXHysitesVHVHCHCH1Fab-5-5-"0005-5-cooCH2CH2FCCH3CH3COO"oocC=constantdomainV=variabledomainH,L=heavy,lightchainsFigure5-21aLhningrPrincipesochmistySnhditoo 2017 W. H. Freeman and CompanyCLTLS,TsinghuaUniversit
CLTLS, Tsinghua University
The Structure of antibodies1.Fab region 2.FcHzNregion3.Heavychain(blue)3withone variable (VH)①domainfollowed byaconstant domain (CH1),ahinge region, and twoHOOCmoreconstant(CH2and2CH3) domains. 4. Lightchain(green)withonevariableVL)andoneconstant(CL)domain5.HOOCCOOHAntigenbinding site4(paratope)6.HingeregionsCLTLS,TsinghuaUniversithttps://en.wikipedia.org/wiki/Antibody#/media/File:lmmunoglobulin_basic_unit.svg
The Structure of antibodies 1. Fab region 2. Fc region 3. Heavy chain (blue) with one variable (VH) domain followed by a constant domain (CH1), a hinge region, and two more constant (CH2 and CH3) domains. 4. Light chain (green) with one variable (VL) and one constant (CL) domain 5. Antigen binding site (paratope) 6. Hinge regions. https://en.wikipedia.org/wiki/Antibody#/media/File:Immunoglobulin_basic_unit.svg CLTLS, Tsinghua University
The Structure of antibodiesNH2HzN3HzNVH①CH16CL20SHOOCCOOCH2Constant?regionsImmunoglobulinCH3C,domain( CHdomains)HOOCCOOH4https://en.wikipedia.org/wiki/Antibody#/media/File:lmmunoglobulin_basic_unit.svgFIGURE28.36Thecharacteristic“collapsed b-barrel domain"known as the immunoglobulin fold.CLTLS,TsinghuaUniversitBiochemistry6thbyReginaldH.Garrett,CharlesM.Grisham,2017CengageLearning
The Structure of antibodies Constant regions https://en.wikipedia.org/wiki/Antibody#/media/File:Immunoglobulin_basic_unit.svg FIGURE 28.36 The characteristic “collapsed b‐barrel domain” known as the immunoglobulin fold. Biochemistry 6th by Reginald H. Garrett, Charles M. Grisham，2017 Cengage Learning CH1 CH2 CH3 CL CLTLS, Tsinghua University